This invention relates to the aerial stringing of electrical conductors, and more particularly to a tool for facilitating the movement of a conductor from one side to the other of an insulator string extending from a support tower to a yoke plate or the like.
U.S. Pat. No. 4,053,706 describes a suspension bracket assembly for supporting high voltage conductors in an inverted V configuration, so that the upper conductor is situated between the lower ends of the insulators which support the suspension bracket, thus minimizing electrical stress on the insulator lower ends.
However, in order to install the upper conductor on said suspension bracket assembly, it is necessary to move it through one of the insulator strings. A method for doing this is described in U.S. Pat. No. 4,022,431.
U.S. Pat. No. 4,189,828 describes an installation tool, or conductor transfer device, for temporarily mechanically bypassing the lower end of one of the supporting insulator strings, so that said end can be temporarily opened to permit moving of the upper conductor through it to the installation position on the suspension bracket assembly.
The tool described in U.S. Pat. No. 4,189,828 has an upper frame with a clamp arm assembly at the upper end thereof for engaging the conductor string at a point remote from the bracket assembly or yoke plate; and a lower arm having a lower end engageable with said assembly or plate. The frames are slidably movable toward and away from each other on a pair of guide pins, and such linear movement is provided by a hydraulic cylinder. Disadvantages of this tool are (i) a clamp assembly structure which is cumbersome to operate and (ii) the risk of binding of the sliding frame with respect to the guide pins.
Accordingly, an object of the present invention is to provide an improved conductor transfer device of the general type disclosed in U.S. Pat. No. 4,189,828, the disclosure of which is incorporated herein by reference.